Earth Day Network is an alliance of 5,000 groups in 184 countries
working to promote a healthy environment and a peaceful, just,
sustainable world.
URL: http://www.earthday.net/

World Water Day,
from the IRC International Water and Sanitation Centre.(G)

The international observance of World Water Day is an initiative that grew out of
the 1992 United Nations Conference on Environment and Development (UNCED) in Rio
de Janeiro. The United Nations General Assembly designated 22 March of each year
as the World Day for Water.
URL: http://www.worldwaterday.org/

World Water Monitoring Day was created with two major purposes in mind. First,
to serve as an educational platform to introduce people to the importance of
water monitoring and connect them personally with efforts to protect and
preserve their local watersheds, and second, as a means of expanding the base
of information available about the health each watershed over time.
URL: http://www.worldwatermonitoringday.org/